Practically all radio frequency (RF) and antenna systems utilize a range of components such as phase shifters, power splitters, power combiners, and RF hybrids. For phased array applications, these functions are typically implemented at every element in the phased array which greatly increases system size, weight, cost, and complexity.
Quadrature hybrids or other differential phase generating hybrids may be used in a variety of RF and antenna applications. In an example embodiment, quadrature hybrids may be used for generating circular polarization signals, power combining, or power splitting. In particular, branchline hybrids may be used for a variety of functions where generation or summation of quadrature signals is desired. Applications include generation of polarization signals, power combining, power splitting, balanced amplifiers, and the like. Due to its distributed nature, a prior art branchline hybrid may be limited operating over a relatively narrow band of frequencies (typically 10% bandwidth) and require significant physical space to be produced, particularly at lower frequencies where wavelengths are longer, such as C-band or below. In various embodiments, the outputs of a quadrature hybrid have approximately equal amplitude and a 90° phase difference. In other typical embodiments, a quadrature hybrid is implemented as a distributed structure, such as a branchline hybrid coupler. However, often multiple component types are needed to meet design and manufacturing specifications. The various types of implemented components increase manufacturing costs and design time.